Al-Ghaza¯lı¯’s Philosophical

distinction at all. The third argument that al-Ghaza¯lı¯ objects to in the fi rst dis-

cussion about the world’s pre-eternity is thus probably not from the works of 

Avicenna. 

92

  From a discussion in a later work, it becomes clear that al-Ghaza¯lı¯ 

understood the difference between the  de re/dha¯tı¯  and  de dicto/was.fı¯   meaning 

of modal statements. In that later work, such as in this example, he was willing 

to understand modal statements  de re/dha¯tı¯  rather than  de dicto/was.fı¯ . 

93

  

 Al-Ghaza¯lı¯’s irritation with the  fala¯sifa ’s treatment of modalities becomes 

clearer in the next passage of the  Incoherence  in which al-Ghaza¯lı¯’s criticism 

is more radical. In two articles published in 2000 and 2001, Taneli Kukkonen 

and Blake D. Dutton examine al-Ghaza¯lı¯’s interpretation of modal terms in the 

 Incoherence . 

94

  Both focus on al-Ghaza¯lı¯’s response to the philosophers’ fourth 

proof for the eternity of the world, which is also debated in the fi rst discussion 

of the  Incoherence . Again, the  fala¯sifa  try to prove the pre-eternity of the world 

from the fact that it has always been possible. This time the argument that 

al-Ghaza¯lı¯ addresses comes from Avicenna. It is based on the premise that 

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possibility cannot be self-subsistent but requires a substrate ( mah.all ) in which 

to inhere. 

95

  Following Aristotle’s argument, Avicenna says that this substrate 

is the  hylé , the prime matter that exists eternally. Its receptivity to the forms 

makes it the substrate of the world’s possibility. Thus, the fact that the world is 

eternally possible proves that the substrate of this possibility, which is prime 

matter, must exist eternally. 

96

  

 In his response, al-Ghaza¯lı¯ denies the premise that possibility needs a sub-

strate. Possibility does not exist in the outside world; rather, it is merely a judg-

ment of the mind: 

 The possibility which they mention reverts to a judgment of the mind 

( qad.a¯ l- ¶aql ). Anything whose existence the mind supposes, [noth-

ing] preventing its supposing it possible, we call “possible,” and if it 

is prevented we call it “impossible.” If [the mind] is unable to sup-

pose its nonexistence, we name it “necessary.” For these are rational 

propositions ( qad.a¯ya¯  ¶aqliyya ) that do not require an existent so as to 

be rendered a description thereof. 

97

  

 Al-Ghaza¯lı¯ repeats this argument in the nineteenth discussion, in which Avi-

cenna claims that the possibility of perishing ( imka¯n al- ¶adam ) can only subsist 

in matter and that purely immaterial beings such as human souls are incor-

ruptible. If that were true, al-Ghaza¯lı¯ says, it would imply that a thing could be 

simultaneously potential and actual with regard to a certain predicate. Affi rm-

ing both the potentiality and the actuality of a given predicate is a contradiction, 

al-Ghaza¯lı¯ objects. As long as a thing is potentially something, it cannot be the 

same thing in actuality. At the root of the problem, al-Ghaza¯lı¯ says, is Avicen-

na’s view that possibility ( imka¯n ) requires a material substrate in which to sub-

sist. This substrate is not required, al-Ghaza¯lı¯ maintains, since when we talk 

about possibility we make no distinction whether it were to apply to a material 

substance or to an immaterial one such as the human soul. 

98

  

 As Kukkonen puts it, al-Ghaza¯lı¯ shifts the locus of the presumption of a 

thing’s actual existence from the plane of the actualized reality to the plane 

of mental conceivability. 

99

  The domain of possibility is not part of what actu-

ally exists in the outside world, al-Ghaza¯lı¯ argues. These modalities are like 

universal concepts, and like the universals such as color or like the judgment 

that all animals have a soul, for instance, their existence is in the mind only. 

The outside world consists of individual objects, and these individuals cannot 

be the objects of our universal knowledge. The universals are abstracted from 

the individual objects that we perceive. “What exists in the outside world (   fı¯ 

l-a ¶ya¯n ) are individual particulars that are perceptible in our senses ( mah.su¯sa ) 

and not in our mind ( ma ¶qu¯la ).” 

100

  Like the universal concept of “being a color” 

( lawniyya ) that we cannot fi nd anywhere in the outside world, the predicates 

“possible,” “impossible,” and “necessary” do not apply to objects outside of our 

mind. Al-Ghaza¯lı¯ takes a nominalist position with regard to the modalities and 

argues that modal judgments are abstract notions that our minds develop on 

the basis of sense perception. 

101

  

 

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 In his objection to Avicenna’s conception of the modalities, al-Ghaza¯lı¯ 

makes innovative use of Ash  ¶arite ontological principles. 

102

  When the Ash ¶arites 

denied the existence of natures, they rejected the limitations that come with the 

Aristotelian theory of entelechy. Viewing things as the carriers of possibilities 

that are bound to be actualized restricts the way these things may exist in the 

future. These restrictions unduly limit God’s omnipotence, the Ash ¶arites say; 

and as long as things are regarded by themselves, the possibilities of how they 

exist are limited only by our mental conceivability. Additionally, when Ash ¶arites 

talk about something that exists, they mean something that can be affi rmed 

( athbata ). 

103

  To claim that there presently exists in a thing an inactive capacity 

to be different from how it presently is—meaning that there exists such a pos-

sibility in that thing—is really to say that there presently exists something that 

does not exist. 

104

  This is a contradiction, and Ash ¶arites subsequently denied the 

existence of nonactive capacities: existence is always actual existence. 

105

  This is 

why Ash ¶arites refused to acknowledge the existence of natures that determine 

how things react to given situations. Natures are, in essence, such nonactive 

capacities. In the course of this study, it will become clear that the status of mo-

dalities marks an important crossroads between Avicenna and al-Ghaza¯lı¯ that 

determines their positions on ontology. Al-Ghaza¯lı¯’s philosophical shift stems 

from a background in  kala¯m  literature, a change that merits closer look. 

 The Different Conceptions of the Modalities in  falsafa  and  kala¯m  

 Ancient Greek philosophy used and distinguished several different modal para-

digms, but none included the view of synchronic alternatives. Our modern view 

of modalities is that of synchronic alternative states of affairs. In that model, 

“[t]he notion of logical necessity refers to what obtains in all alternatives, the 

notion of possibility refers to what obtains at least in one alternative, and that 

which is logically impossible does not obtain in any conceivable state of af-

fairs.” 

106

  In contrast, Aristotle’s modal theory has been described as a statistical 

interpretation of modal concepts as applied to temporal indefi nite sentences. 

To explain a temporally unqualifi ed sentence of the form “S is P” contains an 

implicit or explicit reference to the time of utterance as part of its meaning. If 

this sentence is true whenever uttered, it is necessarily true. If its truth-value 

can change in the course of time, it is possible. If such a sentence is false when-

ever uttered, it is impossible. 

107

  Simo Knuuttila clarifi es that in ancient Greek, 

modal terms were understood to refer to the one and only historical world of 

ours, and “it was commonly thought that all generic types of possibility had to 

prove their mettle through actualization.” 

108

  

 Avicenna’s view of the modalities is not signifi cantly different from the sta-

tistical model of Aristotle that connects the possibility of a thing to its temporal 

actuality. 

109

  Here he followed al-Fa¯ra¯bı¯, who teaches that the word “possible” 

or, to be more precise, “contingent” ( mumkin ) 

110

  is best applied to what is in a 

state of nonexistence in the present and stands ready either to exist or not to 

exist ( yatahayyi 7u an yu¯jada wa an la¯ yu¯jada ) at any moment in the future. 

111

  

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Avicenna shares this temporal attitude toward the modalities: the necessary is 

what holds always, and the contingent is what neither holds always nor holds 

never. 

112

  This position, which represents mainstream Aristotelianism, seems to 

imply that something has to exist at one point in time in order to be possible. 

For Avicenna, however, “what neither holds always nor holds never” refers to 

predications about things in the outside world as well as those that exist only in 

the mind. The “heptagonal house” ( al-bayt al-musabba ¶  ), for instance, may never 

exist in the outside word but will at one point in time exist in a human mind 

and is therefore a possible being. 

113

  For Avicenna, the principle of plentitude is 

valid for existence in the mind (   fı¯ l-dhihn ) but not for existence  in re   (    fı¯ l-a  ¶ya¯n ), 

that is, in the outside world. It is contingent that some houses, or all houses, 

are heptagonal, since the combination of “house” and “heptagonal” is neither 

necessary nor impossible. Here Avicenna clearly divorces modality from time. 

The possibility of a thing is not understood in terms of its actual existence in 

the future but in terms of its mental conceivability. 

114

  By acknowledging that 

some beings such as the chiliagon—a polygon with so many sides that it can-

not be distinguished from a circle—exist in the mind but will probably never 

exist in the outside world, Avicenna recognizes possibilities that are never actu-

alized  in re . 

115

  To say that “all animals are humans” is a contingent proposition 

because we can imagine a time in which there is no animal but man, in spite 

of the fact that such a time probably never existed  in re . 

116

  The contingency of 

the proposition is not verifi ed by the future or past existence of a certain state 

of affairs  in re  but rather through a mental process, namely, whether such a 

state can be imagined to exist without contradictions. 

117

  The phrase, “all white 

things,” may have two different meanings according to the context in which it 

is uttered. It may refer to all beings that are white at the particular time when 

the statement is made or to those possible beings that are always described as 

being white every time they appear in the mind (  ¶inda l- ¶aql ). 

118

  

 In principle, Avicenna does not part with the Aristotelian statistical under-

standing of the modalities. In order to be possible, something must exist for at 

least one moment in the past or future. Mental existence ( al-wuju¯d f ı¯-l-dhihn ), 

however, is one of the two modes of existence in Avicenna’s ontology. Whether 

something exists in our minds depends upon whether it is the subject of a 

predication. There is no ontological difference between whether a thing exists 

in reality or merely in the human mind. 

119

  

 Avicenna’s understanding of existence is signifi cantly different from that 

of his predecessors. Al-Fa¯ra¯bı¯, for instance, followed Aristotle and taught that 

predication itself includes no statement of existence. When one states that “Soc-

rates is just,” it need not follow that Socrates is existent. Avicenna disagreed 

because the nonexistent cannot be the subject of a predication; any predication 

gives mental existence to Socrates. 

120

  Allowing two modes of existence and ac-

cepting mental existence as equal to existence  in re  leads Avicenna to develop 

an understanding of possibility as that which is actually conceived in the mind 

( ma  ¶qu¯l bi-l-fi  ¶l ). 

121

  Any possible subject of a true predication is a possible being. 

This dovetails with Avicenna’s view that what is possible by itself ( mumkin bi-

dha¯tihi ) is determined on the level of the quiddities ( ma¯hiyya¯t ). The quiddities 

 

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have three modes: in themselves, in individuals (   fı¯ a ¶ya¯n al-ashya¯ 7 ), and as sin-

gular objects of thought (   fı¯ l-tas.awwur ). 

122

  In themselves, the quiddities are in 

a state prior to existence and are pure possibility by themselves; the moment a 

quiddity is conceived in the human mind, it is given existence. When the mind 

proceeds to another thought, the thing just pondered or imagined falls from 

existence. This example highlights that for Avicenna, the concepts of possibility 

and existence are closely connected. Possibility is what can be existent at any 

moment in our mind, and existence is actualized possibility either  in re   or  in 

the mind. The modalities can, therefore, also be expressed as simple modes of 

existence: necessary is what cannot but exist; possible (or rather: contingent) is 

what can exist but must not exist; impossible is what cannot exist. In each of 

the three modes, existence is understood as being either  in re  or in the mind, 

although in most contexts it is both. For Avicenna, the division between neces-

sary and contingent is one of the prime divisions of being that is known as  a 

priori . 

123

  Although strictly speaking, this is still a temporal understanding of the 

modalities, it puts the modalities on the plane of mental conceivability. For all 

practical matters, the modalities are not connected to existence in time but to 

existence in the mind (   fı¯ l-dhihn ). 

124

  

 Avicenna took an important step toward understanding possibility as a syn-

chronic alternative state of affairs. He himself never achieved such an under-

standing, however, because in his ontology, there can be no alternatives to what 

actually exists. We have already said that Avicenna’s metaphysics was necessi-

tarian, meaning that whatever exists either in the outside world or in the human 

mind is the necessary result of God’s essence. 

125

  In chapter nine of  De interpre-

tatione,  Aristotle had already argued that what presently exists can be defi ned as 

necessary: what is, is by necessity. Avicenna applies the distinction—known to 

us from al-Fa¯ra¯bı¯’s commentary on this section of  De interpretatione —between 

the modal status a being has by itself and its modal status as coexisting with 

other things. By itself, there is only one being that is necessary by virtue of itself 

( wa¯jib al-wuju¯d bi-dha¯tihi ), and that is God. This being cannot but exist. Con-

sidered by themselves, all other beings are merely possible ( mumkin al-wuju¯d 

bi-dha¯tihi ); God’s creative activity, however, makes the existence of these beings 

necessary. Once a thing that is only possible by virtue of itself comes into being, 

it is necessary by virtue of something else ( wa¯jib al-wuju¯d bi-ghayrihi ). It is, fi rst 

of all, the necessary effect of its proximate effi cient cause. That cause, however, 

is itself the necessary effect of other effi cient causes, which proceed in a chain 

of secondary effi cient causes from God. Everything that we witness in creation 

is possible by virtue of itself and necessary by virtue of something else, ulti-

mately necessitated by God. 

126

  

 In the Western philosophical tradition, in which Avicenna became an in-

fl uential contributor after the translation of his works into Latin during the 

thirteenth century, the introduction of the synchronic conception of modality 

is credited to John Duns Scotus (d. 1308). An avid reader of Avicenna, Duns 

Scotus claimed that the domain of the possible is an  a priori  area of what is in-

telligible and as such does not have any kind of existence in the outside world. 

Among his successors in Latin philosophy, this led to a view in which modality 

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lacks an essential connection with time. This disconnect allowed for alternative 

possibilities at any given time, as well as the development of a notion of pos-

sible words, some of them not actualized. 

John Duns Scotus, however, was not “the fi rst ever” to employ a synchronic 

conception of modality, as some Western historians of philosophy assume. 

127

  

Such a view had already been developed in Ash ¶arite  kala¯m . The notion of God 

as a particularizing agent ( mukhas.is. ), who determines, for instance, when the 

things come into existence, is an idea that appears in the writings of al-Ba¯qilla¯nı¯ 

and of other Ash ¶arite authors. 

128

  The idea of particularization ( takhs.ı¯s. )  implic-

itly includes an understanding of possible worlds that are different from ours. 

The process of particularization actualizes a given one of several alternatives. 

Yet the alternatives to this world—which would be: “X comes into existence at 

a time different from when X actually comes into existence”—are not explic-

itly expressed or even imagined. The  kala¯m  concept of preponderance ( tarjı¯h. ), 

however, explicitly discusses the assumption of possible worlds. The prepon-

derator distinguishes the actual state of being from its possible alternative state 

of nonbeing. Whereas it is equally possible for a given future contingency to 

either exist or not exist, each time a future contingency becomes actual, the pre-

ponderator decides between an actual world and an alternative world in which 

that particular contingency is nonexistent. In  kala¯m,  the idea of preponderance 

( tarjı¯h. ) already appears in the work of the Mu ¶tazilite Abu¯ l-H.usayn al-Bas.rı¯ in 

the context of human actions. 

129

   Abu

¯ l-H

. usayn was a younger contemporary of 

Avicenna, and he had received a philosophical education. He also developed a 

particularization argument for the existence of God. 

130

  Based on these develop-

ments within  kala¯m ,  al-Juwaynı¯ was the fi rst Ash ¶arite who developed a strin-

gent argument for God’s existence based on the principle of particularization. 

131

  

In his  Balanced Book  in the  Letter for Jerusalem , and in his  Scandals of the Esoter-

ics,   al-Ghaza¯lı¯ reproduces versions of this proof. Al-Ghaza¯lı¯’s versions contain 

strong overtones of Avicenna’s ontology: because everything in the world can 

be perceived as nonexisting, its nonexistence is by itself equally possible as 

its existence. Existing things necessarily need something that “tips the scales” 

( yurajjih.u ) or preponderates between the two equally possible alternatives of 

being and nonbeing. God is this “preponderator” ( murajjih. ), who in this sense 

determines the existence of everything that exists in the world. 

132

  

 Avicenna’s view of modalities does not break with Aristotle’s statistical 

model, yet he postulates possibility as mental conceivability, thus taking a step 

toward an understanding of possibility as a synchronic alternative state of af-

fairs. We see one element of such a synchronic alternative in Avicenna’s de-

scribing God as the “preponderator” ( murajjih. ) between the existence of a thing 

and its alternative of nonexistence. Avicenna’s ontology of quiddities, wherein 

existence depends on a separate act of coming-to-be, fosters the idea of God as 

a preponderator between being and nonbeing. In Avicenna’s major work,  The 

Healing , however, the word “preponderance” ( tarjı¯h. ) and its derivates do not ap-

pear that often. It is much more prominent in one of Avicenna’s early treatises 

on divine attributes. This small work,  Throne Philosophy   ( al-H

. ikma al- ¶arshi-

yya ), made a signifi cant impression on al-Ghaza¯lı¯. When he reports Avicenna’s 

 

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teachings on this subject, for instance, he stresses the idea of preponderance 

and follows Avicenna’s language from his  Throne Philosophy  more than the lan-

guage of  The Healing . 

133

  

 Even though the Ash ¶arites readily embraced the concept of preponderance, 

they rejected Avicenna’s understanding of the modalities. For al-Ghaza¯lı¯, Avi-

cenna’s lack of distinction between existence in mind (   fı¯ l-dhihn ) and existence